/*
 * @Descripttion: 
 * @version: 
 * @Author: zzh
 * @Date: 2021-07-25 12:43:14
 * @LastEditors: zzh
 * @LastEditTime: 2021-07-25 13:40:23
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include <pthread.h>

#define MAX_EVENT_NUMBER 1024
#define BUFFER_SIZE 10
//将文件描述符设置成非阻塞
int setnonblocking(int fd)
{
    int old_option = fcntl(fd, F_GETFL);
    int new_option = old_option | O_NONBLOCK;
    fcntl(fd, F_SETFL, new_option);
    return old_option;
}

void addfd(int epollfd, int fd, bool enable_et)
{
    epoll_event event;
    event.data.fd = fd;
    event.events = EPOLLIN;
    if (enable_et)
    {
        event.events |= EPOLLET;
    }
    epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
    setnonblocking(fd);
}

void lt(epoll_event *events, int number, int epollfd, int listenfd)
{
    char buff[BUFFER_SIZE];
    for (int i = 0; i < number; ++i)
    {
        int sockfd = events[i].data.fd;
        if (sockfd == listenfd)
        {
            struct sockaddr_in client_address;
            socklen_t client_addrlength = sizeof(client_address);
            int connfd = accept(listenfd, (struct sockaddr *)&client_address,
                                &client_addrlength);
            addfd(epollfd, connfd, false);
        }
        else if (events[i].events & EPOLLIN)
        {
            printf("event trigger once\n");
            memset(buff, 0, BUFFER_SIZE);
            int ret = recv(sockfd, buff, BUFFER_SIZE - 1, 0);
            if (ret <= 0)
            {
                close(sockfd);
                continue;
            }
            printf("get %d bytes of content:%s\n", ret, buff);
        }
        else
        {
            printf("something else happended\n");
        }
    }
}

void et(epoll_event *events, int number, int epollfd, int listenfd)
{
    char buff[BUFFER_SIZE];
    for (int i = 0; i < number; ++i)
    {
        int sockfd = events[i].data.fd;
        if (sockfd == listenfd)
        {
            struct sockaddr_in client_address;
            socklen_t client_addrlength = sizeof(client_address);
            int connfd = accept(listenfd, (struct sockaddr *)&client_address,
                                &client_addrlength);
            addfd(epollfd, connfd, true); //开启et模式
        }
        else if (events[i].events & EPOLLIN)
        {
            printf("event trigger once\n");
            while (1)
            {
                memset(buff, 0, BUFFER_SIZE);
                int ret = recv(sockfd, buff, BUFFER_SIZE - 1, 0);
                if (ret < 0)
                {
                    if (errno == EAGAIN || errno == EWOULDBLOCK)
                    {
                        printf("read later\n");
                        break;
                    }
                    close(sockfd);
                    break;
                }
                else if (ret == 0)
                {
                    close(sockfd);
                }
                else
                {
                    printf("get %d bytes of content:%s\n", ret, buff);
                }
            }
        }
        else
        {
            printf("something else happened\n");
        }
    }
}
int main(int argc, char *argv[])
{
    if (argc <= 2)
    {
        printf("usage:%s ip_address port_number\n", basename(argv[0]));
    }
    const char *ip = argv[1];
    int port = atoi(argv[2]);
    int ret = 0;
    struct sockaddr_in address;
    bzero(&address, sizeof(address));
    address.sin_family=AF_INET;
    inet_pton(AF_INET,ip,&address.sin_addr);
    address.sin_port=htons(port);
    int listenfd=socket(PF_INET,SOCK_STREAM,0);
    assert(listenfd>=0);
    ret = bind(listenfd,(struct sockaddr* )&address,sizeof(address));
    assert(ret!=-1);
    ret=listen(listenfd,5);
    assert(ret!=-1);
    epoll_event events[MAX_EVENT_NUMBER];
    int epollfd=epoll_create(5);
    assert(epollfd!=-1);
    addfd(epollfd,listenfd,true);
    while(1)
    {
        int ret=epoll_wait(epollfd,events,MAX_EVENT_NUMBER,-1);
        if(ret<0)
        {
            printf("epoll failure\n");
            break;
        }
        
        lt(events,ret,epollfd,listenfd);
        // et(events,ret,epollfd,listenfd);
        
    }
    close(listenfd);
    return 0;
}